Steam pressure gauge protector



STEAM PRESSURE GAUGE PROTECTOR Filed May 3. 1932 Zjwvwntot L. fizo z zz aon becoming frozen Patented June 6, 1933 o; meme o. rnonrson, or oKLanoimA errY, OKLAHOMA rnnssunng Application filed May 3,

This inventionrelates toimprovements in means for -protecting pressuregauges on steamrboilers. V, a v v The primary object of the present inventionis;toprovide anatt'achment which will protect the boiler pressure gauge by preventing live steam from cominginto contact with lei 12A stillfurtlier object of the the; gaugevspring and affecting the same in suchlawlnannerwas-to cause it to give inaccuratereadings l 1 Q .cAnothejr object off theinvention is to providea pressure gauge protector which will give protection v, to the gauge at periods when 'the same may beexposed to freezing temperthereof and incapable of correctly operating lwhenpressure is applied thereto.

invention 1s tol-providea'; pressure gauge protector which is ,ofgsimple 1 design; and strong and durable construction; easy to install iand so designed .thatitwill not e sily get out of; order.

. A1 Finest important object of this invention is; to providej aprotector of thecharacterdejscribedwhich is separate from the gauge 1t self, but is so constructed that it may bereadily attachedto a,-standard gauge-such as are i used "on practically I l eonsiderationpfthe following detailedde scription taken infconnection with the accom- .panying odrawing forming part of this spec all boilers and 1 readily connectedtoithe steam line. i r ,1 Theinventijon will 'bebe'st understood from 3 the understanding, however, that the invention iis not confined to any strict conformity with the'showing of the drawing abutumayu-be changed or modified so "long as such ichanges or, modifications 'mark no ma- .terial departure from the salient features of the invention as expressed in the appended l a 1 Eliefigure represents the l device embody- J.indicate';- corresponding. parts throughout .ing the present invention, in longitudinal section, showingja steam pressure gauge att d ere a l ,1 {Referring now .more, particularly, to 1; the

drawing,where in like numeralsof reference the se erfl-vie at e n me a 1 i c e genereauen rnornc'ron;

1932:. Serial no. 608,968;

ally the casing of the protector device embodying the present invention. As shown, this casing 1 is in the form of an elongated tubular body having the reduced or constrict:

ed upper and lower ends 2 and 3 respectively, :5

each of which'is interiorly threaded as indicated at 4. Adjacent the lower end of the casing 1 is a laterally directed exteriorl threaded nipple 5 which is integral wit the casing and opens thereinto as shown. The '5 outer end of this nipple has the annular groove 5' formed therein, the inner wall of which groove is sloping so as to forma substantially cone-like body about the passage of the nlpple. y l

Connected with the nipple 5 is atubular extension 6 which has a collar 7 formed about one vend for abutment against the forward end of the nipple andthe end of thearmfi adjacentthis collar is formed as shown, to

fit into the annular recess in nipple 5. r M y Onuthe tubular arm 6 is a swivel coupling 8 which engages collar/T tightly against the end thereof.

The opposite endlof the armfi is turned upwardly as indicated at 9 and is interiorly threaded as shown,

the end of the ardsteam pressure gauge 10. e l t i As shown, thetubular bodyl is of such a length thatvvhen the gauge 10 is mounted upon the arm 6 in the manner shown the top of the tube at the interior thereof will be in substantially the same plane as the top of 8 the gauge body.

The threaded lower end3 of the casing 1 has threaded therein the nipple portion 11 of a pet-cock which is indicatedas a whole by .the numeral .112. character which has formed as a part thereof a hexagonal section 13 and a threaded lower portion 13 to which a steam pipe (not shown) may be attached to connect the device to the boilerjin association withwhich 9 it is to be used. It willbe seen from the fig- .ure that the handle of the pet cock extends parallel tothe casing 1 when the pet cock is v open to permit the passage of steam into the pressure gauge protector, this being the northe nipple and draws the 5 to receive the threaded nipple 9} which forms a portion of a stand- This pet-cookie of the 9 of this plug 14 is that it against the bodyo-f mal position of the handle under working conditions and the handle thus not projecting outward where it would be likely to be struck and shifted to close or diminish the passage through the pet cock.

The interior of the pet-cock nipple 11 is also threaded to receive a stand tube 12 which extends longitudinally through the casing 1 and terminates at a of the casing, as illustrated. i

In the upper end of the casing lthere is removably mounted an ai This bushing has the passage 15 therethrough enlarged at the inner end to form 'avalve seat 16, and within this enlarged inner portion of the passage 15 there is located a valve plug 17 which is normally maintained in contact with the seat 16 by a coil spring 18 which in turn is held in position by a pin member 19 which passes through the body of this bushing. It'will, of course, befunderstood that any suitable means may be provided for maintaining the valve body 17 upon'its seat or for maintaining" the spring 18 in position, the elements here shown being preferred.

1 The necessity for this valve 17 is due to the fact that steam is continually condensing in the space above the level of the glycerine or water which fills the tubular casing 1, this space at the upper end of the tubular casing 1 constituting in effect a cooling chamber. When the condensed water accumulates on the top of the glycerine (if glycerine is used) to a degree where it will pass over the top f the tube 12, the water will run down this tube to the boiler and during this period, which occurs in an instant about every 45'secon'ds, the steam will be stopped. Under these circumstances, the pressure within theupper end of the chamberwill become less than atmospheric and the valve will open for an instant until the pressure is equalized, This opening and closing movement of the valve is very quick and is just enough to keep a proper pressure in the upper portion of the %tub'u=larca sing land thus prevent variations in the-glycerine column and in the gauge which would occurwerethis valve not provided. The plug 14 or air valve bushing permits the valve to be readily withdrawn whenever necessary either for replacement 'or cleaning but the most important feature permits the inspectorsgatge to be attached to the tubular casing whenever the devicehas to be inspected by the'boiler inspectors.

In operation the casing 1 is 'filled with glycerine to the height of the upper en d of the tube 12; 'It will, of course, be understood that when the casing is filled the gauge arm 6 and the gauge 10 will be filled also; When the steam enters the casing'l it will pass upwardly through the pipe or tube-'12 to the up'perjend jo-f the casing and exert pressure glycerine therein, through point adjacent the top r valve bushing 14.

'it be used 'tionof steam in'to "ing, a tubular arm which the pressure will be transmitted to the gauge. The volume of glycerine in the casing 1 will, of course, be reduced slightly as some of it is forced over into the gauge and when the steam pressure drops the reduction in pressure within the upper portion of the casing will be compensated for by the introduction of air through the valve biish'in'g 4 as previously stated. By the provision of the valve in the top of the casing 1 the collapse "of the tubes or weakening of the other parts of-the gauge 10 is prevented through the reduction of pressure in the gauge when the fire in the steam boiler to which the gauge is attached is turned off or' drawn during the existence of a full head of steam.

From the foregoing description it will be readily seen thatthe pressure of steam within the boiler, to which the gauge and protector may be attached, will be indicated by the gauge without the steam coming into contact with the elements in the gauge and it will also be appreciated that, since glycerine can withstandex'tremely low temperatures without freezing, the elements of the gauge will be protected when the gauge is exposed to freezing temperatures.

While in the foregoing specification the gauge protector has been described as being filled with glycerine and it is preferred that in this condition, it is, of course, to be understood that the invention is not to be limited to the use of the protector with glycerine as it may be allowed to fill with condenser water and the thereby from direct contact It will, of course, be obvious 1y cold locations the use ofglycerine is desirable because of its low if ezing point and in addition glycerine will act as a lubricant for the gauge-parts. I

Having thus described the invention, what is claimed is 1. A protector for steam pressure gauges, "comprising a easing designed to receive a fluid, means for connecting a pressure gauge with said "casing whereby saidfl-u-i'd may flow -into the gauge, said casing being only artially filled with the fluid, means for introducing "steam into the casing above the fiu'id parts 'rotected with t e steam. that in extremelevel', and an automatically opening valve Wheirthe pressure in the upper portion or the gauge is less than atmospheric.

2. A steam gauge protector, comprisingan elongated tubular body designed to be verti- "c'ally disposed and to be p'i rtial'ly"filled with a fluid having low freezing and non-corrodin'g qualities, a tube extending longitudinal- 1y of said casing from the bottom to apoi n't adjacent the 'top thereof, means for coupling afsteampipe with said tube for theintroduc- "the up er part of the eashaving conneetien at one foo ing said fluid from the casing, a

I an interiorly threaded opening,

chamber inward of the aperture disposed in said chamber and yieldingly held end with the lower part of said casing and valve in said bushing yieldingly held to its adapted to have a pressure gauge connected at its other end, said arm and auge receivushing having screw-threaded engagement with the upper end wall of the tubular body, the bushing having an air inlet aperture and a valve and a valve against said aperture, the valve opening inwardly upon a reduction of pressure within the upper portion of the tubular body.

a 3. protector for steam pressure gauges comprising a tubular metallic casing having an integral outstanding exteriorly screwthreaded nipple intermediate its ends wherebyit may beiconnected to a standard steam gauge, the lower end of the casing having a pet cock below the casing having a nipple threaded in said opening, the pet cock being connectible with a source of steam, a centrally disposed tube of relatively small vdiameter having steam-tight engagement with the nipple of the ct cock and extending upward centrally through the tubular casing nearly to the upper end thereof, the space between the central tube and the casing being filled with liquid, the upper end of the casing having a screw-threaded aperture, a hollow bushing disposed in said aperture and having an aperture through its end communicating with the exterior air, and a valve yieldingly held in position to close said aperture in the bushing but opening inwardly on a reduction in pressure in the upper portion of the tubular casing.

4. A protector for steam pressure gauges comprising a tubular metallic casing having an integral outwardly extending screwthreaded nipple intermediate its ends, a tubular extension engageable against the end of said nipple and having a shoulder, the outer end of the tubular extension being angled and interiorly screw-threaded for engagement with the nipple of a standard gauge, a collar engaging the screw-threads of the nipple and engaging said shoulder whereby to detachably hold the extension against said nipple, the lower end of the tubular casing having an interiorly screw-threaded opening, a pet cock having a nipple screw-threaded within said opening, the pet cock having a valve and a handle for the valve, a valve opening communication to the pet cock when the handle is turned into parallel relation to the axis of the casing, having steam-tight engagement with the nipple of the pet cock and extending upwardly centrally from the tubular casing nearly to the upper end thereof, the space central tube and the casing being adapted to be filled with liquid, a bushing having screwthreaded engagement with the upper end of the tubular casing and an inwardly opening seat but moving inward when the pressure within the upper end of the casing is reduced below a predetermined point.

5. The combination with a standard pressure gauge having a nipple of a protector adapted to be disposed between the pressure gauge and the steam line, the protector comprising a tubular metallic casing having interiorly screw-threaded openings at its upper and lower ends and having a nipple projecting outward from the side wall of the casing adjacent its lower end, the nipple being exteriorly screw-threaded, a tubular connecting element having screw-threaded engagement with the nipple of the gauge, means for detachably connecting said element with'the nipple of the casing, a pet cock having screwthreaded engagement with the opening at the lower end of the casing, a tube of relatively small diameter having steam-tight engagement with the pet cock and extending upward through the casing nearly to its upper end, the central tube extending upward nearly to the upper end of the gauge, the space between the central tube and the outer casing being filled with liquid whereby the gauge will be filled with liquid,

bushing 1n the upper end of the casing, and means automatically admitting air into the space at the upper end of the casing above the liquid when pressure Within the upper end of the casing is reduced below atmospheric.

In testimony whereof I hereunto aflix my signature.

LESTER O. THOMPSON.

a tube of relatively small diameter between the p a removable 

